At sunset, the fossil quarry of Mirzan is a forlorn place. The diggers have gone home exhausted, and only the foreman, Amar Taghlaoui, and his five tiny daughters watch the sun go down over jumbled slabs of granite. The desert here is reg, or loose stone, and its boulders are packed tight with thousands of fossilized sea creatures. Taghlaoui picks his way over them with gingerly care, smoothing away dark orange dust to reveal what look like ghostly snails and monstrous shrimps. He is a haggard man in his 40's with blackened, brutalized hands, an illiterate Berber living off the only riches that the Sahara now offers: fossils. Mirzan is his livelihood, and it lies in what was once the floor of a vast prehistoric ocean. "It was a sea," he says. "But God has willed it dry."

We are a few miles outside the remote Moroccan desert town of Erfoud. The day's heat still shimmers on manganese stones that have been burned a surreal blue by the sun. In the distance looms a desolate pink-tinted mountain called Hmor Lagdad, "the Rose-Cheeked One" in Arabic. On the other side lies Algeria. "That mountain is packed with fossils," Taghlaoui says.

As we climb over Mirzan's jagged, rocky slopes, Taghlaoui's girls come scampering after me with little trays of polished snail-like ammonites and cardboard boxes of dinosaur teeth. I reach a working trench filled with an ancient-looking compressor and a broken crane; the girls, dressed in head scarves and leggings, follow me and begin pressing me to buy a dino tooth or two. I point to a squidlike shape in the rock face and ask them what it is.

"It's an Orthoceras," one girl chirps back in Berber.

"What about this?"

I pick out a fossil about the size of my middle finger from a tray. It looks like a nightmarish sea-spider bristling with little black spines.

"Trilobite!" the girls sing.

Taghlaoui tells them softly to put their trays away. The quarry is certainly an odd place to grow up -- a scattering of wretched bivouacs, bleating goats and cinder-block huts. We start picking up stones at random, and he shows me the astonishing imprints of marine life 300 million years ago. "We're like fishermen living off the sea," Taghlaoui says. "Except that our sea is dead."

Flinching in the scalding wind, the emaciated Taghlaoui shows me how his workers hack giant, six-ton lumps of rock from the trench using vertical holes punched by the compressor and then raise them with a car jack before rolling them carefully onto the rock face. It does not look like jolly exercise in the 120-degree heat. The aim is to turf up thousands of rare fossils, which can then be prepared as individual specimens for discerning fossil collectors in America, Germany and Japan. The desert around Erfoud, in fact, has become one of the richest and most lucrative sources of fossils on earth, especially for trilobites -- the ancient relatives of today's insects, spiders, centipedes, crabs and lobsters.

Erfoud is now considered the trilobite capital of the world. Many collectors, furthermore, call Morocco the world's greatest "fossil capitalism" economy. Paleontologists and collectors from the West come here almost continually, sifting through quarries like Mirzan for unusual trilobite specimens. A rare trilobite can fetch sky-high prices in Western fossil boutiques or on Internet auction sites. Indeed, once Taghlaoui and his men have hacked it out of the stone, a trilobite from here could well end up in some millionaire's home halfway around the world. (The actor Nicolas Cage, for example, is a major trilobite collector; Bill Gates is said to be one, too.) In one of the stranger twists of the global economy, the collecting whims of rich Westerners have led impoverished nomads across the Sahara to take up the digging trade.

"The oases are drying up," Taghlaoui says with a sigh. "Our villages were dying." Squinting at the spectacular pink sunset, he makes a grim joke. "These fossils will keep us from going extinct."

Trilobites became extinct about 230 million years ago, just before the advent of the Triassic age. In Morocco, most specimens survive from the distant Devonian period, between 345 and 405 million years ago. Trilobites, which swarmed in their millions in warm oceans, were among the first arthropods -- creatures characterized by segmented body appendages and a hard exoskeleton. More than 10,000 trilobite species, ranging in size from a few millimeters to two feet, have been dug up around the world. Some are spined and some are not. (The spiny variety are generally considered more valuable.) A few of them are cute, but most look ferocious, rather like the creatures in Ridley Scott's movie "Alien."

Their names are as exotic as their looks. There is the common Phacops Rana Africana, an oval bug with a bulbous head. Its cousin, the Spiny Phacops, bristles with tiny erect spears. There is the Dicranurus Monstrosus, whose name says it all -- a nightmarish tangle of legs, spines and feelers. Some species even have long trident-shaped appendages spouting from their heads. One of these is the Comura Trident, which appears to have probed the ocean with a long, spatulalike prong as well as four rhino-style horns attached to its head.

'We're like fishermen living off the sea,' says Taghlaoui, who spends his life digging fossils out of desert rock. 'Except that our sea is dead.'

In today's booming fossil market, a good specimen of the Comura Trident can easily fetch $3,000. Other trilobites are worth much more than that. A rare Psychopyge with 51 free-standing spines was recently bought for $22,000. A newly discovered Astropyge species brought in a cool $28,500. The price for a top-notch trilobite prepped by an American "preparator" often ranges from $15,000 and $20,000.

"I really keep my pulse on the fossil market, and trilobites are the hottest thing right now," says David Herskowitz, director of the natural history department at Butterfields auction house in San Francisco. What makes the prehistoric bugs so popular? The answer seems to rest in their sheer diversity. In Morocco alone, new species are dug up every year, so the market never stagnates. What's more, there are just enough of them to allow connoisseurs to indulge in elaborate cross-referencing and comparisons. "You may as well ask why people pay millions for Faberge eggs or Roman glass," Herskowitz says. "Trilobites are cool. They're strange, bizarre animals. They're glamorous. They're beetles from Mars!"

Henry Galiano is the owner of Maxilla & Mandible, the premier fossil store in New York. "People have cash, and they want something to collect," he explains. "If you want to collect Impressionist paintings, you're out of luck. There's nothing left. But fossils are a new frontier. They're inexhaustible."

The zooming prices of the estimated $40-million-a-year fossil industry have primarily enriched American importers and collectors. But Moroccans are also increasingly finding ways to profit from the trilobite trade. Berber entrepreneurs contract diggers to work remote trenches deep in the desert and then offer the most promising specimens for sale via the Internet. Acting as canny middlemen between East and West, a few Saharan dealers have become wealthy men. Other locals have tried to cash in, however, in a less salubrious manner -- by conducting a lively trade in cunning fakes, fashioned with everything from epoxy to car cement.

"There's a lot of dirty stuff out there," says Mark Norell, chairman of the division of paleontology at the American Museum of Natural History. "Fossils are very trendy now, very lucrative -- and everyone wants to profit."

Fakes aren't a problem just in Morocco. Last year, a birdlike dinosaur fossil from Liaoning Province in China was bought by the Dinosaur Museum in Blanding, Utah, and hailed on the cover of National Geographic as a missing evolutionary link between dinosaurs and birds. But the fossil was bogus: a Chinese farmer had craftily placed a dinosaur tail onto the body of a fossilized bird. The National Geographic Society recanted its "discovery" with much blushing and stammering.

Moroccan forgeries are similarly notorious, with thousands of wholly or partly faked trilobites circulating in fossil shows, stores and catalogs. At the annual Tucson Gem and Mineral Show, paranoid trilobite dealers often take their Moroccan specimens to experts like Karl Flessa, professor of geosciences at the University of Arizona, for verification. A Tucson television station once filmed Flessa as he sawed into a Moroccan specimen, filling his lab with smoke from burning plastic. "Spectacular," Flessa said on the air. "But the saw reveals all."

David Herskowitz is equally skeptical. "With most specimens coming directly from Morocco, I'd say at least 20 percent of each piece is fake, no matter what the dealer says. People in Morocco are poor. As they say, necessity is the mother of invention."

Richard Eisenman, a prominent fossil dealer in New Jersey, says that the fudging of fossils has long been quietly tolerated. "I'm sure that even in the Museum of Natural History there's a fair bit of it," he says. "A lot of stuff is simply glued together. Trilobites are nearly always broken. If a specimen is 75 percent original, that's great." The problem in Morocco, he explains, is that fakers will actually change the specimen's species to make it look more unusual. "They'll even add a long nose or pair of whiskers, or lump two of them together."

The Mirzan quarry, where Amar Taghlaoui works, doesn't mess around with fakes. It is owned by a small Arab company in Erfoud called Usine Marmar. In addition to hawking trilobites on the global market, the company sells polished fossilized table tops hewn from the quarry for $2,000 apiece. The company's profits, however, don't trickle down. The laborers, who spend nine hours a day sledgehammering rock in temperatures approaching 125 degrees, are paid only $4 a day. "We get paid so little," Taghlaoui says bitterly as the moon rises over the desert. "But it's better than nothing."

Squatting with his girls around him, Taghlaoui makes us mint tea in the traditional Saharan way, breaking lumps of sugar into the pot and then pouring the tea into glasses from on high. Around us are piles of gypsum fossils. He picks up one and pours a little hot tea on it. Immediately, its dun-colored surface brightens; he tilts it with a grin. "Sometimes we clean them with Coca-Cola," he says. He drips a little tea onto a fragment that contains the beaded eye of a Phacops trilobite. It comes eerily to life. "I want to send my daughters to school," Taghlaoui murmurs, stroking his youngest's hair. "Fossils will send them all to school, God willing."

Erfoud lies at the end of the desert road, right in the middle of the mighty Ziz oasis. It's a bone-dry market town of pale red streets and houses with mud walls and turquoise shutters. In a funky local bar named the Fez Palace, fossil traders often gather in the evening for a cold Flag beer.

The most successful of them is a quietly informal man in his 40's named Brahim Tahiri. He has promised to take me to his prepping lab out in the desert. Tahiri smiles sheepishly. "I built my lab out of town," he says in his fluent French, "because everyone is jealous of me here."

Outside Erfoud, the desert begins at once. Tahiri's Mercedes rattles over the unmarked desert tracks. His "farm," it turns out, consists of a few irrigated fields of melons fed by a private well, with an outdoor fossil-prepping workshop set in the middle. We stroll past piles of hot, mauve rocks bursting with trilobites, each species laid out separately.

A lone worker sits shoeless amid the debris with a pot of glue. (The adhesive is alcohol-based and is mixed with pebbles from the same rock.) He is fastening the two halves of a plate of rock together. Tahiri's 40 privately contracted quarry workers will often crack a promising-looking boulder apart like a hazelnut to find a trilobite inside. After Tahiri has paid them a few dollars for the two halves, his six preppers glue them back together and start working at the rock from the outside, using pencil-thin sandblasters. Tahiri shows me the sableuse, or blaster: it looks like a dentist's drill, with a needle-fine point. For a simple spineless specimen, the blasting could take two days. Finally, the intact beast re-emerges whole. A dusting of aluminum then imparts a fine polish to the surface, and it is ready for export.

We step around a small sergui, or irrigation channel, and go into the generator shed. Inside two enormous metal casserole dishes with lids, Tahiri keeps his prize specimens. He hands them around with evident glee: a fully prepped Kengaspis (a minuscule bug from the Cambrian period) and a Spiny Phacops perched on a stone base.

"We're finding four or five new trilobite species every year," he says. "I stockpile them, then release them onto the market bit by bit. If there's anything fabulous out there in the desert, I'll get it first."

Later, I have dinner at Tahiri's house. Although he has made millions from the fossil trade, the house retains the feel of a spartan Berber tent; the only obvious luxury is a Hewlett-Packard computer. As we eat an extravagant tagine stew with our fingers, he tells with relish of the legendary beginnings of the Moroccan fossil boom.

"In the early 70's," he explains, "a French Canadian dealer named Claude Ben David came to Erfoud and began asking around for fossils. Well, as you know, there's no money here, no jobs. So my eldest brother, Ali, went off into the mountains with a stone ax to look for these weird animals buried in the stone. We had no idea what the hell they were!"

David was followed by one Bill Barker, an American hippie who first came to Morocco to drop out. Barker is now based in Tucson and is one of the top American fossil dealers. "At that time," says Barker, "the drought was killing off the date harvests, and there was a labor surplus. They had no fossils laws either -- so there was an open window of opportunity."

Barker and Ali Tahiri developed the first trilobite business based around the rich deposits of Mount Issoumour, 75 miles west of Erfoud. When Ali died in a car crash, the young Braheem took over the family business. "Now fossils are our local treasure," Tahiri he. "All the kids in Erfoud now study these fossils in books! It's a godsend."

Tahiri's principal rival in the Erfoud fossil business is Abdullah Aaronson. Abdullah runs a company called Sahara Overland, which conducts mineralogical and paleontological tours of the desert. He takes me one morning to the nearby village of Rissani, the site of the biggest fossil market in the Sahara.

Abdullah leads me down a crumbling street known locally as Zenkot Lahjor, or the Alley of the Rocks. Here there are dozens of hole-in-the-wall fossil stores where knowing collectors spend hours sifting through shelves of rocks hewn from Mount Issoumour and its sister lode, Mount Atchana. The preppers crouched by the doorways use ancient vices and hammers made from old car piston caps to tool away at their specimens. Of course, not all of what they sell is genuine.

"Actually, these places are full of what we call 'composites,"' Abdullah explains. "Fakes have been the curse of the Moroccan market over the last few years. All the nomads hear that fossils are money spinners so they make casts, or moulages, from originals. You can make them in half an hour." In one store, he picks up a slightly rubbery looking Trident embedded in a half-shell of chipped stone. "It's totally fake," Abdullah murmurs in English. In another boutique, we see some enormous plates with several trilobites embedded in them. These mishmashes, which have been stuck together from various locations, are known as "trilobite pizzas."

He picks up another Trident. This one has an authentic body, but the trident has been glued on afterward. "They smother it with battery powder to give it that black coal color," he says. "It's pretty good as fakes go. It doesn't fool me, but it might fool dealers in America."

As we walk past metal doors painted with yellow diamonds, Abdullah waves off various fossil hustlers who try to take him aside. He says that dealers from the High Atlas town of Midelt come down to the Sahara to scoop up cheap fakes and then offload them in the United States at absurd markups. "God knows where they end up. One wonders how many museums have them in their collections!"

We stop in yet another one-room store, belonging to a man called Said. The walls are festooned with photocopies of trilobite anatomies. "I have some Devonian stuff just in," cries Said as we walk in. "Take a look."

Abdullah and Said haggle over two unprepped Phacops in Maghrebin dialect. To the untrained eye, the specimens look like two ordinary rocks wrapped in newspaper. Said laughs and shakes his head. "You're a hard man, Abdullah."

"Eight hundred dirham. You're killing me anyway."

Mint tea is brought out, and the deal is subtly finalized with a touching of the hands. Eight hundred dirhams is about $72.

We all drink the scalding tea, and both Moroccans jovially swear they have been robbed.

"You're a hard man," Said says again, evidently delighted with his 800 dirhams.

Abdullah holds up one of the Phacops. "After I prep them, they'll be worth quite a bit more than 800 dirhams," he murmurs in English. "They're nice. And they're real."

In Morocco, there is nothing illegal about making fakes; the sin is merely to pass them off as real. This permits a large gray area to persist, and into this gray area a growing number of poor Saharans willingly step. They are not sure why Westerners adore these hideous little dead animals, but they are sure that money is money.

To see how trilobites can be "manufactured," Abdullah and I set off for Mount Issoumour in a jeep. It's a brutal daylong voyage across the open desert. Passing the villages of Tiguerna and Alnif, we see ramshackle fossil stalls everywhere. Wind howls through ruined mud casbahs. "There are two economic activities here," Abdullah says dryly. "Emigration to France -- and fossils."

Mount Issoumour is a forbidding sight; it is a gigantic fortresslike rectangle of Devonian rock with sheer purple cliffs. These cliff faces are striated by tiny lines: fossil beds. As we drive around the mountain, the desert glitters eerily with exposed barite. We pass miles of open fossil trenches where the trilobites are especially rich. Each digger has his own spot; he leaves his equipment there each night. "The entire fossil business," Abdullah says, "comes down to these thousands of freelance individuals with their pickaxes." A sandstorm rises, and suddenly everything disappears into pure heat.

At last, we arrive at a forger's farm. I'm greeted by a middle-age man named Mujan in a cream djellaba with a terrible scar over his left eye. "Shall we kill a goat kid?" he asks smilingly. We politely decline. On the baked ground around the house lie the usual piles of shattered crinoid stems and trilobites. In a shaded yard, his three sons squat among bottles of car cement, Italian industrial glue and bicycle-spoke chisels. Pairs of spectacles hang from nails in the walls. Mujan's eldest boy, who is 14, is mixing Devonian-era dust with glue to produce an emulsion that will blend with the rock of a trilobite.

I discreetly ask if they can make a fake for me. "Sure," Mujan says. "It'll take about half an hour. Have some tea while you're waiting."

I sit in the garden and feed the goat some alfalfa. The boys are soon busy, their feet trundling a rickety homemade lathe. I had expected some conspiratorial secrecy, but it's clearly no big deal.

Neither is it particularly complicated. The boys first take a mold of a small Comura Trident impressed from the real thing. They fill the two halves of the mold with the dust-car-cement mixture tinted to the correct color and then seal them tight. It takes about 20 minutes to dry; while we wait, we sip tea. I ask them skeptically if they know how old their fossils are. "Ordovician," they say blandly. The father is very proud: "Everything, it is from a book!" The boys then crack open the mold and on one surface there now lies embedded a perfect little Comura made of car cement. It is slightly purplish and needs a bit of touching up with car-battery powder to make it blacker. "There," Mujan says, holding it to me. "One Trident, 300 million years old." It has taken 29 minutes exactly. The boys wipe their hands on their tattered pants and squint. It is an artisanal production line.

Before leaving, I also buy a Pyschopyge, whose head has been similarly concocted out of the same rudimentary materials.

"Enjoy your trilobites!" Mujan cries as we walk away. The whole family comes out to wave. I say I'll put the Comura proudly in my bedroom. They look at me aghast; as we pull away in the jeep, I see that they are shaking their heads slowly and sadly. In the bedroom? What strange taste foreigners have!

We drive back to Erfoud through the dusk. Downtown on Avenue Mohammed V, the muezzins are wailing, and the streets are packed with black-veiled women. The fossil shops piled with ammonites and T. Rex teeth glow under a few bulbs. Behind the houses, preppers sit under contorted open-air shelters made of wire and rotting canvas, pedaling away at their lathes. There is an odd atmosphere of methodical madness to it all. The whole town, I realize, is one big prep lab.

"It's fossil capitalism, all right," says Abdullah. We greet a dealer in the street named H'mid, who shakes my hand shyly. "I used to live in a cave," he says gaily. "Without fossils, you know, this place would be zero." The implication is that he has been saved from neolithic oblivion by ancient arthropods.

Later, in the Fez Palace bar, I am treated to a Flag beer by its owner, the exquisitely mannered Monsieur Sadoq.

"So you have seen our great Mount Issoumour?" he says augustly. "How do you like our fossils?"

I say I like them very much.

He smiles mysteriously. "They are beautiful."

Then we peer down for a moment at the bar, where polished trilobites swirl in the marble counter. Sadoq squeezes my hand.

"And soon," he adds in a conspiratorial whisper, "we'll be rich as well, praise Allah."